The benefit of provisional application 61/641,530, filed May 2, 2012 on behalf of inventors Jean-Guy Gagne and James Rogers, is claimed under 35 U.S.C. 119(e).
This disclosure is related to hardware fasteners, more particularly to what has been characterized as speed nut fasteners.
A conventional speed nut contains sheet metal or plastic prongs that act as a single thread for fixing substrates or other work pieces by attachment to an externally threaded fastener, such as a machine screw. In contrast to traditional nut fasteners, the speed nut does not require successive turning of the screw until tightening is achieved. Instead, speed nut attachment involves forced application of the speed nut to the screw that has been inserted through a hole in a substrate. The prongs are flexed without engaging with the screw threads. At the extent of travel of the speed nut, a screwdriver can be applied to turn the screw up to a full rotation to engage a screw thread and compress the substrate. The prongs then exert pressure on a single screw thread. The screw can be removed by turning in the opposite direction until the last screw thread is disengaged.
The speed nut provides the advantage of speed of installation, at the cost of weakness of structure, as compared to the traditional nut fastener. The speed nut prongs are weakened by flexure occurring substantially at their thin base connections to the fastener body. A further disadvantage is that the speed nut, when applied, can be misaligned with the screw thus increasing stresses on the device. Misalignment can also result in reducing the force necessary to maintain attachment by the single internal thread, especially compared with multiple thread attachment of a traditional nut fastener.
Needs thus exist for an improved speed nut that produces less localized stress, that distributes flexure, that can provide greater attachment strength from separate internally threaded portions, and that can prevent misalignment with the externally threaded fastener during installation.